[PATCH 20/23] nfctype5: Discard extra byte in RMB response data

[Mark Greer]

Sometimes there can be an extra byte in the response data for Read
Multiple Blocks (RMB) commands so discard it whenever that happens.

Signed-off-by: Mark Greer <mgr...@animalcreek.com>
---
 plugins/nfctype5.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/plugins/nfctype5.c b/plugins/nfctype5.c
index a91d8f5..d6eec3c 100644
--- a/plugins/nfctype5.c
+++ b/plugins/nfctype5.c
@@ -654,7 +654,7 @@ static int t5_read_multiple_blocks_resp(uint8_t *resp, int 
length, void *data)
        uint8_t blk_size = near_tag_get_blk_size(tag);
        size_t data_length;
        GList *records;
-       int err;
+       int err, expected_len;
 
        DBG("");
 
@@ -665,9 +665,16 @@ static int t5_read_multiple_blocks_resp(uint8_t *resp, int 
length, void *data)
                goto out_done;
 
        length -= NFC_HEADER_SIZE;
+       expected_len = sizeof(*t5_resp) +
+                      cookie->nb_requested_blocks * blk_size;
 
-       if (length != (int)(sizeof(*t5_resp) +
-                           (cookie->nb_requested_blocks * blk_size))) {
+       /*
+        * Sometimes an extra byte is returned in RMB response data.
+        * Discard the extra byte whenever that happens.
+        */
+       if (length == (expected_len + 1)) {
+               length--;
+       } else if (length != expected_len) {
                err = -EIO;
                goto out_done;
        }
-- 
2.13.0